In-situ electrode fabrication from polyaniline derived N-doped carbon nanofibers for metal-free electro-Fenton degradation of organic contaminants

Electro-Fenton (e-Fenton) process is a highly efficient technology for refractory wastewater treatment. However, electrode fabrication from powdered carbon catalysts usually requires additional binders, which is expensive, non-scalable and arduous process. In this study, the electrode was in-situ fabricated using N-doped carbon nanofibers derived from carbonization of polyaniline (PANI), electrodeposited on graphite-felt substrate without any binder. The as synthesized electrode was used for in-situ electro-generation and activation of H2O2 to( center dot)OH radicals for degradation of organic pollutants without metal catalyst. Potassium hydroxide was used to tailor the functional groups and reactive surface area of the electrode. The optimized electrode showed H2O2 production of 0.306 mg cm(-2) h(-1) and 85% of phenol removal with 42% of mineralization in 180 min. Mainly the N functional groups (graphitic and pyridinic N) function as active sites for electro-generation and activation of H2O2 to (OH)-O-center dot radicals, which was the main oxidant for degradation of pollutants.